358 PROCEEDINGS OF THE ACADEMY OF [1898. 



NOTES ON THE ARCTIC RED-BACKED MICE. 

 BY GEKRIT S. MILLER, JR. 



" We challenge the proof that Mus rutilus is not a circumpolar 

 species." The view thus forcibly expressed by Dr. Elliott Coues 

 twenty-one years ago 1 fairly represents current opinion in regard to 

 the Arctic Red-backed Mice, at least so far as concerns those of 

 Alaska and the Old World. From time to time during this period, 

 Evotomys rufocanus has been recognized as a distinct form ; but 

 Evotomys rutilus is universally regarded as an exceptionally homo- 

 geneous and wide-ranging circumpolar species. Writing of the 

 Red-backed Mice in 1897, Mr. Vernon Bailey says : " The only 

 circumpolar species [of Evotomys] is the Arctic E. rutilus, which 

 does not undergo any considerable change throughout the cir- 

 cumference of the Arctic zone." 2 



A recent examination of the Arctic red-backed mice in the Uni- 

 ted States National Museum convinces me that the Evotomys rutilus 

 of authors is far from the unvarying species that it has been repre- 

 sented. While the material at hand is too limited to form the 

 basis of anything like a final revision, it clearly proves the distinct- 

 ness of Evotomys rufocanus, and also the existence of three forms of 

 so-called rutilus, one in the extreme north of Europe, one in Kam- 

 tschatka, and one in Alaska. 



The Mus rutilus of Pallas came from Siberia immediately east of 

 the Obi. As no specimens from this region are available for com- 

 parison, the question of the exact identity of the species must, for 

 the time being, remain open. Geographical considerations lead me 

 to apply the name rutihis provisionally to the most westerly of the 

 Old World forms rather than to the one occurring in Kamtschatka. 

 The latter is the Arvicola wosnessenskii of Polyakoff. Its identity 

 with Richardson's Arvicola rubricatus from Bering Strait, is too un- 

 certain to be worthy of serious consideration at present. The lat- 

 ter is described as slate color on the back, and nearlv scarlet on 

 the sides — a color pattern quite unknown in the genus Evotomys. 



1 Monogr. N. Am. Eodentia, p. 138. 



2 Proc. Biolog. Soc. Washington, XI, p. 113. 



